This invention is directed to improvements over the cement lasting machine disclosed in U.S. Pat. applications Ser. No. 227,376, filed Feb. 18, 1972, now U.S. Pat. No. 3,775,797 and Ser. No. 325,701, filed Jan. 22, 1973 now U.S. Pat. No. 3,758,904.
The aforementioned machine includes an arrangement for supporting bottom-up a shoe assembly formed of a last having an upper mounted thereon and an insole located in its bottom with the opposite side portions of the upper margin extending upwardly of the insole. Lasting instrumentalities on each side of the support arrangement are caused to first engage the opposite side portions of the upper and then wipe the margins of these upper portions against the insole. The lasting instrumentalities are each mounted for inward-outward movement on a base, and the bases are located on opposite sides of and outwardly of the support arrangement with each base also being mounted for inward-outward movement. Initially each base is located in an outer position with respect to the support arrangement, so that the shoe assembly can be readily placed on the support arrangement, and each lasting instrumentality is in an outer position with respect to its associated base. The bases are then moved inwardly, together with the lasting instrumentalities, to inner base positions wherein the lasting instrumentalities are close to but not in engagement with the sides of the shoe assembly. This is followed by a movement of the lasting instrumentalities inwardly of their outer positions on the bases so as to enable them to engage the opposite side portions of the upper and wipe the upper margin portions against the insole.
In the aforementioned machine, the lasting instrumentalities, when the bases have completed their inward movement, must always be disengaged from the shoe assembly and spaced a desired close distance from the shoe assembly. With the support arrangement of the aforementioned machine, each lasting instrumentality, when its associated base has completed its inward movement, will be a different distance from the shoe assembly or may actually engage the shoe assembly depending on whether the shoe assembly is for a right foot or for a left foot due to the differences in the asymmetrical constructions of the left foot and the right foot shoe assemblies. In order to overcome this difficulty and to insure that the lasting instrumentalities are spaced the desired distance from the sides of the shoe assembly regardless of whether a left foot shoe assembly or a right foot shoe assembly is being operated on, the machine, in accordance with a first aspect of this invention, has been improved by providing a mechanism for selectively moving the part of the support arrangement that supports the toe portion of the shoe assembly laterally in one of two opposite lateral directions.
In the aforementioned machine, the wiping of the opposite side portions of the upper margin against the insole is performed by lasting tools or straps that first apply relatively light back-up forces to the margin portions to fold them part way toward the insole. After this, cement nozzles are caused to travel along the sides of the insole periphery and outwardly thereof to the extent permitted by the margin portions, which are backed up by the lasting tools or straps, and to apply cement into the corners between the margin portions and the insole periphery. This is followed by causing the lasting tools or straps to apply relatively heavy wiping forces to the margin portions to wipe the margin portions against the insole and attach them to the insole by way of the cement. The purpose of having the margin portions folded part way toward the insole during the travel of the nozzles and the extrusion of cement through the nozzles is to cause the folded margin portions to create a barrier between the upper margin and the insole that inhibits the creeping of cement between the margin and the insole and then between the upper and the sides of the last. Shoe assemblies are so constructed that one side of the shoe assembly has a relatively pronounced reentrant portion and the other side of the shoe assembly has a less pronounced reentrant portion. The side of the shoe assembly having the relatively pronounced reentrant portion is different for left foot shoe assemblies and right foot shoe assemblies. The angle formed between the side of the last and the bottom of the last on the side of the shoe assembly having the relatively pronounced reentrant portion is an acute angle which is smaller than the angle, which is close to a right angle, formed between the other side of the last and the bottom of the last. Therefore, the folding of the upper margin part way towards the insole on the side of the shoe assembly having the relatively pronounced reentrant portion is needed to create the barrier between the upper margin and the insole while this folding is not needed to create the barrier on the other side of the shoe assembly. Moreover the folding of the margin part way toward the insole on the side of the shoe assembly having the less pronounced reentrant portion tends to prevent the nozzle traveling along this side of the shoe assembly from reaching the periphery of the insole in the corner in which it is traveling which is undesirable for the subsequent cementatious attachment of the upper margin to the insole. In order to overcome this problem, in a second aspect of the invention only the lasting tool or strap on the side of the shoe assembly having the relatively pronounced reentrant portion is caused to apply the relatively light back-up force to fold the upper margin part way toward the insole.
The aforementioned machine is intended to operate on a shoe assembly in which the upper margin of at least one end portion of the shoe has been wiped against the insole and to apply cement by a nozzle along a course of the upper margin that extends rearwardly of a boundary between an unwiped upper margin portion and the wiped end margin portion. The nozzle is connected to a yieldable drive means to effect forward-rearward movement of the nozzle and is caused to be located in a starting position in the corner between the unwiped margin portion and the corresponding portion of the insole periphery a particular distance rearward of the boundary. The drive means is then released to move the nozzle forwardly while the nozzle stays in the corner until the nozzle arrives at the boundary. Concomitantly with the arrival of the nozzle at the boundary, a reversing mechanism is actuated to cause the drive means to move the nozzle rearwardly while the nozzle stays in the corner and to cause cement to be extruded from the nozzle during its rearward movement. With this arrangement, the particular distance between the starting position and the boundary varies in accordance with the length of the shoe assembly and the forward-rearward location of the actuator for the reversing mechanism therefore has to be adjusted for each shoe assembly length.
In a third aspect of the invention, the inconvenience referred to at the end of the preceding paragraph is overcome by actuating the reversing mechanism a predetermined time after the drive means is released which time is equal to or greater than the minimum time it takes for the nozzle to move forwardly from the starting position to the boundary. Should the nozzle arrive at the boundary before the reversing mechanism is actuated, it will pause at the boundary, due to meeting resistance to forward movement at the boundary and due to its being driven forwardly by a yieldable drive means, until the reversing mechanism is actuated.
Each lasting instrumentality of the aforementioned machine is comprised of a plurality of separated side by side heightwise extending straps. In the machine operation, the lasting straps are caused to so engage the shoe assembly that a top segment of each strap extends upwardly of the insole and outwardly of a portion of the upper margin. A nozzle is then caused to travel along the insole periphery while yieldable downward and outward forces are applied to the nozzle and cement is extruded through the nozzle to cause the nozzle to bear against the insole and the margin portion and to enable cement to be extruded into the corner between the margin portion and the insole. After this, the nozzle is moved inwardly of the margin and upwardly of the insole and the top segments of the lasting straps are folded downwardly and inwardly against the insole to wipe the margin portion against the insole and attach it to the insole by way of the cement. Due to the separation between the lasting straps, the nozzle has a tendency to snag and get caught in the separation between the lasting straps and not move smoothly along the upper margin. In a fourth aspect of the invention, this difficulty is overcome by making that portion of the lasting straps that extend upwardly of the bottom of the insole when the lasting straps engage the shoe assembly integral instead of separated.